Krumbholz, Theory IV

9th Chords A 9th chord is created by adding that interval (an octave plus a major second) to either a triad or a seventh chord. Although a chordal 9th can be added to any of the four triad types or five seventh chord types, in barbershop harmony the ninth is almost entirely restricted to either major triads or barbershop seventh chords.

THE MAJOR TRIAD WITH AN ADDED 9TH. This type of ninth chord occurs most often when the melody has the chordal 9th, as this passage from the Irish Blessing shows. However, it is possible for the 9th to appear in one of the other voice parts. The way to label this chord is to use the appropriate Roman numeral label along with “add9.”

THE BARBERSHOP SEVENTH CHORD WITH AN ADDED 9TH (also called a dominant ninth chord). The first and obvious problem is that this sonority is a 5-note chord and barbershop uses only four voices at a time! To deal with this issue barbershop arrangers have found two solutions: 1) omit the chordal 5th, or 2) omit the root! Let’s look at each type in turn.

The example below shows a dominant 9th chord lacking the fifth.

Krumbholz, 9th chords, p. 2

When arranged in the barbershop style, this chord is usually used in root position with the chordal 9th most often in the tenor and chordal 7th in the lead, as shown in Lou Perry’s arrangement of Smilin’ Through. There are no special Roman numeral labels to show that the fifth is omitted.

Here’s the same chord, but this time the ninth is placed in the lead. It also is built on the lowered seventh scale step (ßVII).

A second version of the dominant ninth chord OMITS THE ROOT!

Now, you might think that this type of ninth is rare, but, in fact the opposite is true—it’s extremely common, especially when the ninth is part of the melody. (The chordal fifth is almost always placed in the bass.) The B—D—F—A chord above spell a Bø7, but it’s the context that will make clear the it’s actually a G9 chord but without the G. Once you know how to recognize the “rootless” dominant 9th chord, you’ll discover it frequently in barbershop arrangements. Let’s look a few examples. Krumbholz, 9th chords, p. 3

In Down Our Way, the chord on the word “and” appears to be an E ø7 chord, but the context (sand- wiched between a pair of II7 chords) makes clear that this is a C9 chord, with the C missing. (Note that the tenor and bari have the same notes in the last three bars.)

This example, from Sweet and Lovely, contains both types of dominant ninth chords. The first chord on the word “while” is a true dominant ninth chord (containing the root and ninth, with the lead on the ninth, which then drops to the chord root on the word “you’re.” On the word “by” the ninth is in the tenor (which then moves to the root on beat 3), and on the word “my” the ninth is in the bari (which moves to the root on beat 2). In both cases the ninth acts like a decoration, moving down by step to the chord root (changing the chords to simple barbershop seventh chords). Finally, note the use of circle of fifth progression in the last three bars: VI—II—V. This context helps to identify each of the ninth chords as a substitute for a barbershop seventh chord with the same root.